HiJAKing Innate Lymphoid Cells?

The family of innate lymphoid cells (ILCs) consists of a heterogeneous group of cytokine-producing cells that have features in common with adaptive T helper (Th) cells. Cytokines acting through the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathways are key players in both Th and ILC biology. Observations in animal models, supported by evidence from humans, have highlighted the importance of the downstream events evoked by the cytokines that signal through the common IL-2 gamma-chain receptor. Similarly, it is reasonable to assume that therapeutic targeting of this signaling cascade will also modulate ILC effector function in disease. Since a major limitation of gene knockout studies in mice is the complete loss of ILC populations, including NK cells, we believe that an attractive, alternative, strategy would be to study the role of cytokine signaling in the regulation of ILC function by pharmacological manipulation of these pathways instead. Here, we discuss the potential of JAK inhibitors as a drug class to elucidate mechanisms underlying ILC biology and to inform the design of new therapeutic strategies for inflammatory and autoimmune disorders.